package org.apache.lucene.index;

/**
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

import java.io.IOException;

/** A {@link MergeScheduler} that simply does each merge
 *  sequentially, using the current thread. */
public class SerialMergeScheduler extends MergeScheduler {

    /** Just do the merges in sequence. We do this
     * "synchronized" so that even if the application is using
     * multiple threads, only one merge may run at a time. */
    @Override
    synchronized public void merge(IndexWriter writer) throws CorruptIndexException, IOException {

        while (true) {
            MergePolicy.OneMerge merge = writer.getNextMerge();
            if (merge == null)
                break;
            writer.merge(merge);
        }
    }

    @Override
    public void close() {
    }
}
